Linux kernel 2.6.31 released

[allnameswereout]

Linux kernel 2.6.31 is released. User-friendly changelog.

Some specific OMAP3 changes, but I think N900/Maemo5 will run Linux kernel 2.6.30 anyway.

Besides that I didn't see anything particularly interesting for N900/Maemo5 except this perhaps:

1.3. Improve desktop interactivity under memory pressure

PROT_EXEC pages are pages that normally belong to some currently running executables and their linked libraries, they shall really be cached aggressively to provide good user experiences because if they aren't, the desktop applications will experience very long and noticeable pauses when the application's code path jumps to a part of the code which is not cached in memory and needs to be read from the disk, which is very slow. Due to some memory management scalability work in recent kernel versions, there're some (commonly used) workloads which can send these PROT_EXEC pages to the list of filesystem-backed pages (the ones used to map files) which are unactive and can get flushed out of the working set. The result is a desktop environment with poor interactivity: the applications become unresponsive too easily.

In this version, some heuristics have been used to make much harder to get the mapped executable pages out of the list of active pages. The result is an improved desktop experience: Benchmarks on memory tight desktops show clock time and major faults reduced by 50%, and pswpin numbers are reduced to ~1/3, that means X desktop responsiveness is doubled under high memory/swap pressure. Memory flushing benchmarks in a file server shows the number of major faults going from 50 to 3 during 10% cache hot reads. See the commit link for more details and benchmarks. Source

[Bundyo]

Yes, another minor detail is that Scratchbox is not working on 2.6.31.

[lma]

Originally Posted by allnameswereout

I think N900/Maemo5 will run Linux kernel 2.6.30 anyway.

2.6.28 actually, at least according to the latest SDK.

[arj]

Interesting. This sounds like one step closer to fixing the thrashing hell.

[ruskie]

Hmm would be nice to get things like NILFS or ext4(not sure if .28 has that already out of experimental). Would be a better thing for flash devices I'd say

[allnameswereout]

Originally Posted by lma

2.6.28 actually, at least according to the latest SDK.

Hmmm... yes. Its clear choice for reliability. Only reason I'd care for newer kernels is performance; not hardware support.

It is 2.6.28 with a huge diff/patch btw.

[lma]

Originally Posted by allnameswereout

It is 2.6.28 with a huge diff/patch btw.

Yeah, because it's debian-ised, and also contains the arm-linux patches plus Nokia-specific ones that haven't made it upstream yet. But version-wise it's still 2.6.28.

[javispedro]

Originally Posted by Bundyo

Yes, another minor detail is that Scratchbox is not working on 2.6.31.

"Minor"? There go my plans of upgrading to this one!

Could you elaborate?

[Bundyo]

Originally Posted by javispedro

"Minor"? There go my plans of upgrading to this one!

Could you elaborate?

http://lists.scratchbox.org/pipermai...st/001521.html

It gives mmap: permission denied with the setting in sysctl.conf. I wasn't able to fix it at all with the provided solutions.

[scg]

Originally Posted by Bundyo

http://lists.scratchbox.org/pipermai...st/001521.html

It gives mmap: permission denied with the setting in sysctl.conf. I wasn't able to fix it at all with the provided solutions.

This problem is solved in newer versions of scratchbox and qemu. You might want to update to the latest scratchbox manually or

+ install Maemo 5 SDK
+ install cs2007q3-glibc2.5-arm6 and -i486 toolchains into scratchbox
+ modify and run the maemo4-sdk-installer (see attached patch)
+ select the DIABLO_ARMEL target

and start compiling again.